Update on Tuesday, December 14 @ 3:15 p.m. 

City of Monrovia Issues a Proclamation of Existence of Local Emergency

The City of Monrovia has issued a Proclamation of Existence of Local Emergency in response to the rainstorm on December 13 and December 14, 2021, and is activating a virtual Emergency Operation Center. There has been significant movement of mud and debris, along with rocks and boulders, in Monrovia Canyon Park. There is a substantial amount of debris and mudflow within Monrovia Canyon Park causing damage to facilities, roads, parking areas, utility systems and trails. 

Additionally, staff has identified a broken water main in Monrovia Canyon Park caused by the debris flow. The water system in Monrovia Canyon Park, including the running water in bathrooms and drinking fountains, has been compromised. Monrovia Canyon Park has been closed to the public since Thursday, December 9, and will remain closed indefinitely. Although Monrovia Canyon Park is closed, signs for “Do Not Drink the Water” will be placed within the park until the water main can be repaired. 

A Proclamation of Existence of Local Emergency recognizes the existence of a local emergency and assists the City to mobilize resources and provide emergency response. The local state of emergency enables the City to seek reimbursement for expenditures made when responding to the emergency. 

City of Monrovia staff including Public Works, Community Services, Police and Fire, along with the Los Angeles County Department of Public Works, continue to monitor activities in Monrovia Canyon Park and the neighborhoods of Ridgeside and Oakglade Drives.

Phase II Debris and Mudflow Forecast for Neighborhood of Ridgeside Drive and Oakglade Drive 

Thus far, the neighborhoods of Ridgeside Drive and Oakglade Drive have not experienced significant debris or mudflow onto the streets. Throughout the rain event, the Oakglade Debris Basin, a drainage structure, has captured the debris and mudflow. At this time, these neighborhoods remain under an Evacuation Warning. 

Update on Monday, December 13, 2021 at 4:56 p.m.

A strong storm will bring moderate to heavy rain to the LA County area beginning tonight, Monday, December 13, and continuing through Tuesday, December 14.  

Monrovia Public Works, in partnership with the Los Angeles County Department of Public Works, have been actively monitoring the forecast in anticipation of debris and mudflow in the burn area from the recent Bobcat Fire.

In preparation for the rain, the LA County Department of Public Works has issued a Phase II Debris and Mudflow Forecast for the area of Monrovia that is in the neighborhood of Ridgeside Drive and Oakglade Drive. A Phase II forecast indicates residents should anticipate moderate to heavy flooding and mud or sediment deposition on Ridgeside Drive and Oakglade Drive. An Evacuation Warning has been issued for residents living in the areas of Ridgeside Drive and Oakglade Drive. An Evacuation Warning means that there is potential threat to life and/or property, and those who require additional time to evacuate and those with pets and livestock should leave now. In addition, the National Weather Service has issued a Flash Flood Watch to the areas affected by the Bobcat Fire, from 3 a.m. to 6 p.m. on Tuesday. 

Area of Concern

The area below the Oakglade Debris Basin, in the vicinity of Ridgeside Drive and Oakglade Drive, has been identified for potential debris and mud flow. 

Response to the Debris and Mudflow Forecast

Monrovia Public Works has notified residents in this particular neighborhood of the potential debris and mudflow by going door-to-door to provide the information.   

As we are preparing for this rain storm, our priority is the safety of our residents. The following preparations have been put into place to ensure that staff remains vigilant of the evolving situation and can respond as quickly as possible.  

• Monrovia Fire & Rescue will patrol and assess the areas of concern throughout the rain event.
• Monrovia Police Department will provide extra patrol throughout the evening to monitor the hillside areas.
• Monrovia Public Works has prepared for tractors and dump trucks to respond as needed.
• Monrovia Public Works and Los Angeles County Flood Control / Public Works have assessed and cleared the existing drainage infrastructure so that it is available and functional to take on any flows brought on by the rain event.

Contact Information 

Monrovia Police Department 
Non-emergency line: (626) 256-8000
If there's an emergency, dial 911. 

Monrovia Public Works
(626) 932-5575

Gravel (Sand) Bag Available for Residents 

Gravel, along with gravel bag materials, is available at Recreation Park in the parking lot off of East Olive Avenue, near the skate park and Barney Glen Baseball Field.   

• Recreation Park - 620 S Shamrock Ave, Monrovia, CA 91016

Please note that the gravel bags are self-serve. The City will provide the needed bags and gravel and residents must provide their own shovels, gloves and eye protection. To ensure that there is enough for all of the resident who may use them, please take only what you need.  

Monrovia Canyon Park & Hillside Wilderness Preserve Closure

Due to the rain, Monrovia Canyon Park and the Hillside Wilderness Preserve will be closed until further notice. The City will reopen the park when weather permits.

• Debris and Mudflow Potential Forecast
• Rain Season Preparedness Information